A person deposits a sum for 7 years in a bank which gives 8% simple interest. The amount received from the bank after 7 years is given to his friend at 15% simple interest for 4 years. If the interest received from the bank is Rs. 9400 less than the interest received from his friend, find the compound interest from the sum which is deposited in the bank at a 10% interest rate per annum for 2 years.